Lap joint for roofing and the like



P 1938. E. s. LAWRENCE ET AL 2,130,139

LAP JOINT FOR ROOFING AND THE LIKE Filed Sept. 15, 1957 [ml/avatars.-[OM/4E0 5. LHWEENCE m/ 550865 67. MGLm/ HL/N,

Patented Sept. 13, 1938 UNITED STATES LAP JOINT FOR ROOFING AND THE LIKEEdward S. Lawrence and George G. McGlaughlin, Mount Lebanon, Pa.

Application September 13, 1937, Serial No. 163,683

1 Claim.

This invention relates to metal sheet roofing and the like, andparticularly to an improved lapjoint for such sheets.

Heretofore, commercial roofing of the lap- 5 seam type usually employedlapping edges having a sharp inverted V-shaped, longitudinallyextending, crimped edge for joining the adjacent sheets together. Whilesuch roofing has been commercially successful it doeshave some badfeatures, in that it provides a channeled surface which retains moistureand tends to hasten corrosion at the joint and, further, such aconstruction often develops leaks around the nails that are driven downthrough the sharp-edged crown 15 or vertex of both the lapping andlapped edges to hold the joining edges together and the sheets in place.Also, such nailing often, in penetrating the metal of the crown of theridges, resulted in forming deep depressions in the metal or 20 causedexcessive downward drawing of the metal around the nail, sometimesentirely deforming the joint at that point and allowing leakage of thejoint, and, also, providing an excellent well or retainer for water ormoisture, thereby tend- 25 ing to hasten corrosion thereabout, in timeallowing the nail head to pull through the sheets.

Furthermore, when nails are driven into such a sharp crown or vertex, asthat of a V-shaped crimp, they are difllcult to center and often, after30 entering the lapping edge, they are urged down the inclined side ofthe lapped-edge between the Sheets, thus failing to enter the crown ofthe edge and the material to which they are to be fastened which resultsin the sheets not being fastened at that point; Such a condition alsotends to force the Joining edges apart allowiiig leakage along thejoint.

In the present invention, these difllculties have n overcome byproviding a lap-joint having 40 substantially a wide upwardly arcuatedcrown portion which will not retain moisture but rather from whichmoisture and water will tend .to escape.

It is an object of this invention to provide 45 roofing having alap-joint which is inexpensive to manufacture and easy to assemble,assuring a tight joint which is not subject to undue corrosion, and, atthe same time, possessing all the v other qualities required of a goodroofing.

50 Various other objects and advantages of our invention will more fullyappear during the course of the following specification and will be moreparticularly pointed out in the appended claim.

65 In the accompanying drawing we have shown,

for the purpose of illustration, one embodiment which our invention mayassume in practice.

In'the drawing:

Figure 1 is a plan of asection of a roofing sheet, showing the improvedlap-joint of our 5 invention;

Figure 2 is a sectional view taken on the line 11-11 of Figure 1; and

Figure 3 is an enlarged cross-section, similar toFlgure 2 showing theimproved lap-joint.

Metal roofing and the like is made in sheets of a size that can beeasily and conveniently handled. Each of the sheets is usually the same,having side edge portions which are adapted to be joined in overlappedrelationship; and each usually has a formed lapped-edge along one sideand a formed lapping edge along the other side which is adapted tocooperate with the lapping and lapped edges, respectively, of theadjacent sheets to join them, as is well understood by those 0 skilledin the art.

It is to these lapped and lapping edges that this invention relates.There .is shown in the drawing metal roofing sheets 5 and 6, havingalapped-edge i on one side of the sheet and a lapping edge 8 on theopposite side.

The lapped-edge consists of a longitudinally upwardly extending mainridge 9 of substantially an inverted U-shaped cross-section havingdownwardly diverging opposed side-walls I0 connected by an upwardlyarcuated crown portion II, which are yieldable relative to each other.These side-walisterminate in horizontal fiat portions I! which aredisposed substantially in the plane of the body of the sheet. Thehorlzontal flat portion, toward the center of the sheet, terminates in asecond smaller longitudinally extending ridge H of substantially an in-,verted V-shaped cross-section having side-walls H and IS, with the innerside-wall l5 of the V-shaped ridge terminating in the plane and body ofthe sheet. The other horizontal flat portion'terminates in alongitudinally upwardly extending angular flanged edge It, preferably atan angle of about degrees. 45

The lapping edge consists of a longitudinally upwardly extending ridgell of substantially an inverted U-shaped. cross-section which is sub-'stantially larger than the main U-shaped ridge 9 of the lapped-edge andwhich is adapted to receive and house the same, and has downwardlydiverging opposed side-walls I8 and i9, ap-

preciably shorter than the side-walls l0, connected by an upwardlyarcuated crown portion 2' conforming to the crown portion I l of thelappededge. These side-walla terminate in horizontally disposed flatportions Ii which are parallel to and spaced from the horizontal flatportions I! of the lapped-edge. The horizontal ilat portion toward thecenter of the sheet terminates in a downwardly angularly extendingportion 22, which contacts the end of the flanged portion I of thelapped-edge at 23 on its underside, iinally terminating in the plane andbody oi" the sheet. The other'horizontal flat portion ii of the lappingedge terminates in a downwardly angularly extending flanged portion 24,contacting the outside surface oi the inner side I! of the V-shapedridge it of the lapped-edge, which finally terminates in a turned-outedge "substantially in the plane of the sheet.

There is provided on the outer and topmost central portion of thearcuated crown 2| of the U-shaped ridge of the lapping edge I,predetermined spaced indentations 2' which tend to guide and center thepoint of nails through the crown portion of the ridges and the metal ofthe sheet.

It will be noted that the U-shaped ridge of the lapping edge issubstantially larger than the U-shaped ridge of the lapped-edge whichallows the yieldable side-walls ll of lapped-edge, when nailed orfastened, to spring apart or yield until they contact the lowerterminating edges of the side-walls II and it oi the U-shaped ridge ofthe lapping edge. Such a construction allows for excess nailing andeliminates buckling of the edges, as often happens to such edges whichare not constructed according to this invention.

While we have, in this application, specifically shown and described anembodiment of our invention, it will be understood that this is merelyfor the purpose oi illustration and description and that various otherforms may be devised within the scope of our invention, as deiined inthe appended claim. a

We claim:-

A lap-joint for roofing and the like comprising .a,1so,1ao Vsheetsadaptedtooverlapaiongtheirmeeting' edges, each of said sheetshaving a lapped-edge consisting of a longitudinally upwardly extendingmainridgeoisubstantiailyaninverted U-shaped cross-section, said ridgehaving diverging opposed side-walls connected by an upwardly arcuatedcrown portion, each of said side-walls terminating in horizontal flatportions disposed substantially in the plane of said sheet, thehorizontal ilat portion toward the center of the sheet terminating in asecond smaller longitudinally extending ridge of substantially aninverted V-shaped cross-section, the inner side of which terminates inthe plane and body of said sheet and the other horizontal flatportionterminating in a longitudinally upwardly extending angularflanged edge, and a lapping edge consisting of a longitudinally upwardlyextending overlapping ridge of substantially an inverted usshapedcross-section for receiving the top of the U-shaped ridge of thelapped-edge, said ridge of the lapping edge having diverging opposedside-walls connected by an upwardly arcuated crown portion conforming tothe arcuated crown of the U-shaped ridge of the lapped-edge, saidside-walls being spaced farther apart than the side-walls oi theU-shaped ridge of the lapped-edge and each terminating in horizontallydisposed flat portions spaced from and substantially parallel to thehorizontal flat por-

